CA2668282A1 - Caspase inhibitors based on pyridazinone scaffold - Google Patents

Abstract

The present invention relates to a pyridone derivative which can be used as a caspase inhibitor, process for the preparation thereof, and pharmaceutical composition for inhibiting caspase comprising the same.

Description

Description CASPASE INHIBITORS BASED ON PYRIDAZINONE
SCAFFOLD
[ll [2] ~ Technical Field ~

[3] The present invention relates to a pyridone derivative or pharmaceutically acceptable salt thereof as an inhibitor against variaus caspases including caspase-1 [interleukin-1(3-converting enzyme, ICE], caspase-3 [apopain/CPP-32], caspase-8, and caspase-9, and a pharmaceutical compcsition for the inhibition of caspase comprising the same.

[4]

[5] ~ Background Art ~

[6] Caspase is a new kind of cysteine protease in the form of a z (3 z tetramer discovered during the last 10 years. Abaut 14 kinds thereof have been known until now.
Caspase-1(ICE), one of them, is a kind of cytokine and participates in converting the bio-logically inactive prointerleukin-1(3 to the active interleukin-1(3.
Interleukin-1 consists of interleukin-1 a and interleukin-1(3, both of which are synthesized in monocytes in the form of 31 KDa precursor. Only prointerleukin-1(3 is activated by ICE. The pcsitions hydrolyzed by caspase-1 are Asp 27-Qy 28 and Asp16 Ala"'. The hydrolysis of the latter pcsition gives interleukin-1(3. Interleukin-1(3 has been reported to act as an important mediator in causing inflammation (1,3). Caspase-1 has been discovered for the first time in 1989, and the three dimensional structure thereof was determined by X-ray crystallographic method by two independent study groups.

[7] Caspase-3(CPP-32) is broadly studied for its role or mechanism for action, and its three dimensional structure was determined in 1996(2). Caspase-3(apopain) activated from procaspase-3 is hydrolyzed at the pcsition of (P 4)Asp-X-X-Asp(PI ) motif, and the known substrates include poly(ADP-ribcse) polymerase, U1 70,000 Mr small nuclear ribonucleoprotein, catalytic subunit of 460,000 Mr DNA-dependent protein kinase, etc.
The X-ray structure of caspase-7 has been reported to be very similar to that of caspase-3(4).

[8] Caspase-8 and 9 are present in the upstream of caspase-3,6,7, and all of these caspases are known to participate in the apoptosis cascade. The X-ray structure of caspase-8 was determined in 1999(5), and particularly the inhibitors thereof may be advantageausly used for treating the diseases related to apoptosis.

[9] Caspase inhibitors mean those compounds that inhibit the activity of caspase, and so control such symptoms as inflammation, apoptcsis, etc. caused by the caspase activity.
Diseases or symptoms that may be treated or attenuated by administering the inhibitors include the following: dementia, cerebral stroke, brain impairment due to AIDS, diabetes, gastric ulcer, cerebral injury by hepatitis virus, hepatitis-induced hepatic diseases, acute hepatitis, fulminant hepatic failure, sepsis, organ transplantation rejection, rheumatic arthritis, ischemic cardiac diseases, and liver cirnccsis(6).

[10] Among the caspase inhibitors known until now, the mcst noted irreversible inhibitors are the following:
[Chem.1 ]

H O O O
N F ON F
_~; N H O O I i H O O
O O

[11] Both the above inhibitors exhibit their activity based on the common mechanism that they irreversibly inactivate the enzyme to suppress the cell apoptcsis (irreversible, broad-spectrum inhibitor). It has been reported that irreversible inhibitor has much more effective inhibitory activity than reversible inhibitor (7). Both IDN-1965 of IDUN Co. and MX-1013 of Maxim Co. are reported to show activity in cell apoptosis model for hepatic injury (8, 9). These compounds are now in the stage of preclinical test.

[12] The irreversible inhibitor IDN-6556 is now in the stage of phase II
clinical trial as a hepatoprotective agent for hepatitis C patients (10, 6-liver cirrhosis-i).
[Chem.2]

O F
N~,LN O ~ F

F

[13] References:

[14] (1) Inflammation: Basic Principles and Clinical Correlates, 2nd ed., ed by Gallin, Goldstein and Snyderman. Raven Press Ltd., New York. 1992, pp211-232; Blood, 1996, 87(6), 2095-2147.

[15] (2) Wilson, K. P. et al, Nature,1994, 370. 270; Walker, N. P. C. et al.
Cell, 1994, 78, 343; Nature Structural Biology, 1996, 3(7), 619.

[16] (3) Thornberry, N. A. et al, Nature, 1992, 356. 768; Nature Biotechnology, 1996, 14, 297; Protein Science, 1995, 4, 3; Nature, 1995, 376(July 6), 37; Protein Science, 1995, 4, 2149.

[17] (4) Wei, Y. et al, Chemistry and Biology, 2000, 7, 423.

[18] (5) Blanchard H. et al, Structure, 1999, 7, 1125; Blanchard H. et al, J.
of Mol. Biol., 2000, 302, 9.

[19] (6) References for caspase related diseases [20] Dementia: Arch Neuro12003 Mar;60(3):369-76, Caspase gene expression in the brain as a function of the clinical progression of Alzheimer disease. Pompl PN, Yemul S, Xiang Z, Ho L, Haroutunian V, Purohit D, Mohs R, Pasinetti GM.

[21] Cerebral stroke: Proc Natl Acad Sci U S A 2002 Nov 12;99(23):15188-93, Caspase activation and neuroprotection in caspase-3- deficient mice after in vivo cerebral ischemia and in vitro oxygen gluccse deprivation. Le DA, Wu Y, Huang Z, Matsushita K, Plesnila N, Augustinack JC, Hyman BT, Yuan J, Kuida K, Flavell RA, Moskowitz MA.

[22] Brain impairment due to AIDS: J Neurosci 2002 May 15;22(10):4015-24, Caspase cascades in human immunodeficiency virus-associated neurodegeneration. Carden GA, Budd SL, Tsai E, Hanson L, Kaul M, D'Emilia DM, Friedlander RM, Yuan J, Masliah E, Lipton SA.

[23] Diabetes: Diabetes 2002 Jun;51(6):1938-48, Hyperglycemia-induced apoptcsis in mause myocardium: mitochondrial cytochrome C-mediated caspase-3 activation pathxAay. Cai L, Li W, Wang G, Gio L, Jiang Y, Kang YJ.

[24] C~a.stric ulcer: J Physiol Pharmacol 1998 Dec;49(4):489-500, Role of basic fibroblast growth factor in the suppression of apoptotic caspase-3 during chronic gastric ulcer healing. Slomiany BL, Piotrowski J, Slomiany A.

[25] Cerebral injury by hepatitis virus: J Viral Hepat 2003 Mar;10(2):81-6, Cerebral dysfunction in chronic hepatitis C infection. Forton DM, Taylor-Robinson SD , Thomas HC.

[26] Fulminant hepatic failure: C~a.stroenterology 2000 Aug;119(2):446-60, Tumor necresis factor alpha in the pathogenesis of human and murine fulminant hepatic failure. Streetz K, Leifeld L, Grundmann D, Ramakers J, Eckert K, Spengler U, Brenner D, Manns M, Trautwein C.

[27] Sepsis: Nat Immuno12000 Dec;1(6):496-501, Caspase inhibitors improve survival in sepsis: a critical role of the lymphocyte. Hotchkiss RS, Chang KC, SNAa.nson PE, Tinsley KW, Hui JJ, Klender P, Xanthoudakis S, Roy S, Black C, Grimm E, Aspiotis R, Han Y, Nicholson DW, Karl IE.

[28] Organ transplantation rejection: Xenotransplantation 2001 May;8(2):115-24, In vitro prevention of cell-mediated xeno-graft rejection via the FaslFasL-pathway in CrmA-transducted porcine kidney cells. Fujino M, Li XK, Suda T, Hashimoto M, Okabe K, Yaginuma H, Mikcshiba K, G.io L, Okuyama T, Enosaw S, Amemiya H, Amano T, Suzuki S.

[29] Rheumatic arthritis: Prog Med Chem 2002;39:1-72, Caspase inhibitors as anti-inflammatory and antiapoptotic agents. Graczyk PP.

[30] Ischemic cardiac diseases: Am J Physiol Heart Circ Physio12002 Sep;283(3):H990-5, Hypoxia-induced cleavage of caspase-3 and EFF45/ICAD in human failed cardiomyocytes. Todor A, Sharov VG, Tanhehco EJ, Silverman N, Bernabei A, Sabbah HN.

[31] Anti-inflammation: J Immuno12003 Mar 15;170(6):3386-91, A brcad-spectrum caspase inhibitor attenuates allergic airwy inflammation in murine asthma model.
Iwata A, Nishio K, Winn RK, Chi EY, Henderson WR Jr, Harlan JM.

[32] Hepatitis-induced hepatic diseases : i) J Viral Hepat. 2003 Sep; 10(5):
335-42.
Apoptcsis in hepatitis C Kountazras J, Zavos C, Chatzopoulos D.; ii) Apoptosis Dec;8(6): 655-63 Apoptosis participates to liver damage in HSV-induced fulminant hepatitis. Pretet JL, Pelletier L, Bernard B, Coumes-Marquet S, Kantelip B, Mougin C.; iii) Proc Natl Acad Sci U S A. 2003 Jun 24; 100(13):7797-802. Caspase 8 small in-terfering RNA prevents acute liver failure in mice. Zender L, Hutker S, Liedtke C, Tillmann HL, Zender S, Mundt B, Waltemathe M, Gcsling T, Flemming P, Malek NP, Trautwein C, Manns MP, Kuhnel F, Kubicka S.

[33] Liver cirrhosis : i) J Pharmacol Exp Ther. 2004 Mar; 308(3): 1191-6, The caspase inhibitor Idn-6556 attenuates hepatic injury and fibresis in the bile duct ligated mouse.
Canbay A., Fledstein A., Baskin-Bey E., Bronk F.S. Gores GJ.; ii) Hepatology.

Feb.; 39 (2): 273-8, Apoptcsis: the nexus of liver injury and fibrosis. Canbay A, Friedman S, Gores GJ.; iii) Hepatology. 2003 Nov.; 38(5): 1188-98, Kupffer cell engulfment of apoptotic bodies stimulates death ligand and cytokine expression.
Canbay A, Feldstein AE, Higuchi H, Werneburg N, Grambihler A, Bronk SF, Gores GJ.

[34] (7) Wu J. et al, Methods: A Companion to Methods in Enzymology, 1999, 17, 320.

[35] (8) Hoglen N. C. et al, J. of Pharmacoloy and Experimental Therapeutics, 2001, 297, 811.

[36] (9) Jaeschke H. et al, Toxicology and Applied Pharmacology, 2000, 169, 77.

[37] (10) Hoglen N.C. et al, J. Pharmacol Exp. Ther., 2004 , 309(2):634.
Characterization of IDN-6556 (3-[2-(2-tert-butyl-phenylaminooxalyl) -amino] -propi-onylamino)-4-oxo-5-(2,3,5,6- tetrafluoro-phenoxy)-pentanoic acid): a liver-targeted caspase inhibitor.

[38]

[39] ~ Disclcsure ~

[40]

[41] ~ Technical Problem ~

[42] The present inventors have extensively studied to design novel compaunds which can be used as an effective and more selective inhibitor against caspases.

[43]

[44] ~ Technical Solution ~

[45] To achieve such a subject, the present inventors synthesized variaus compaunds, and determined their binding ability and inhibitory activity for caspases. As a result, the inventors have discovered that a pyridone compaund of the following formula (1) does meet such requirements, and completed the present invention.

[46]

[47] ~ Formula 1 ~
[Chem.3]

R6.N NX,~,X

[48] in which [49] R', Rz ,R3, R4, Rs, R6 , R', Rg and X are defined below.

[50] Therefore, the present invention provides the novel pyridone derivative of formula (1) or pharmaceutically acceptable salt thereof having effective inhibitory activity against caspases.

[51] It is another object of the present invention to provide a pharmaceutical composition for inhibiting caspase, specifically a composition for preventing inflammation and apoptosis, comprising the compaund of formula (1) or pharmaceutically acceptable salt thereof as an active ingredient together with the pharmaceutically acceptable carrier.

[52]

[53] ~ Advantageous Effect ~

[54] The compound of formula (I) according to the present invention has an excellent inhibitory activity against caspase, and so can be advantageously used for the treatment of various diseases and symptoms mediated by caspase.

[55]

[56] ~ Best Mode ~

[57] First of all, the important terms in the present invention are defined as follows:

[58] a) C-C -alkyl: Straight-chain or branched hydrocarbons having 1 to 5 carbon atoms, that include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, etc., but are not limited thereto.

[59] b) C3-Cio cycloalkyl: Cyclic hydrocarbons having 3 to 10 carbon atoms, that include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc., but are not limited thereto.

[60] c) Aryl: Aryl gfuup includes all the aromatic, heteroaromatic and their partially reduced derivatives. The aromatic gfuup means a 5 to 15-membered single or fused unsaturated hydrocarbon. The hetercaromatic gfuup means the aromatic gfuup containing 1 to 5 hetero atoms selected from a gmup consisting of oxygen, sulfur, and nitrogen. The aryl gmup includes phenyl, naphthyl, indolyl, quinolinyl, isoquinolyl, imidazolinyl, isoxazolyl, oxazolyl, thiazolyl, etc., but is not limited thereto.

[61] One or more hydrogens in said C 1 -C 5 -alkyl, C 3-C 10-cyclcalkyl or aryl gmup may be replaced with a group(s) selected from the following: acyl, amino, carbcalkoxy, carboxy, carboxyamino, cyano, halo, hydroxy, nitro, thio, alkyl, cyclcalkyl, alkoxy, aryl, aryloxy, sulfoxy, and guanido gmup.

[62] d) Natural amino acid includes the following: Qycine, Alanine, Valine, Leucine, Isoleucine, Serine, Threonine, Cysteine, Methionine, Proline, Aspartic acid, Asparagine, Qutamic acid, Qutamine, Lysine, Arginine, Histidine, Phenylalanine, Tyresine, and Tryptophan.

[63] Further, the present specification includes the following abbreviations:

[64] N-bromcsuccinimide: NBS

[65] O-(7-azabenzotriazol-1-y~-N,N,N',N'-tetramethyluroniumhexafluorophcsphate]:
HATU

[66] N,N-dimethyl formamide: DMF

[67] Dimethylsulfoxide: DMSO

[68] N-methylmorpholine: NMM

[69] 2,2'-Azobis(2-methyl propionitrile): AIBN

[70] 2,2,6,6-Tetramethyl-l-piperidinyloxy, free radical: TEMPO

[71] Lithium bis(trimethylsilyWmide: LiHMDS

[72] N-(2-Hydroxyethy~piperazine-N'-(2'-ethanesulfonic acid): HEPES

[73] 3-[(3-Cholamidopropy~dimethylamino]-1-propanesulfonate: CHAPS

[74] Ethylenediaminetetraacetic acid: EDTA

[75] Dithiothreitol: DTT

[76] The present invention will be explained more in detail below. One aspect of the present invention relates to the pyridone derivative of the following formula (1):

[77] [Formula 1]
[Chem.4]

R6, N
N \ ~X
p R7R1 [78] in which [79] I) R' represents H, C 1 -C 5 -alkyl, C 3-C 10-cyclcalkyl, aryl, or a side chain residue of all the natural amino acids, [80] 11) R2 represents H, C -C -alkyl, C-C -cycloalkyl, aryl, or a side chain residue of all the natural amino acids, [81] II~ R 3 represents H, C -C -alkyl, hydroxy, C-C -alkoxy, or halogen, [82] IV) R4 represents H, C 1 -C 5-alkyl, C 3-C 10-cycloalkyl, or aryl, [83] V) R 5 represents H, C 1 -C 5 -alkyl, C 3 -C 10-cycloalkyl, or aryl, [84] VI) R 6 represents H, C -C -alkyl, C-C -cycloalkyl, or aryl, [85] VII) R' and Rg independently of one another each represent H, C-C -alkyl, C-C -cyclcalkyl, or aryl, [86] VIII) X represents -CH OR9 (R9 is C-C -alkyl, C-C -cycloalkyl, or ary~, -CH

OC(=O)R'o (R'o is C 1 -C 5 -alkyl, C 3-C 10-cycloalkyl, or aryl), or -CH 2 -W
(W is halogen), or pharmaceutically acceptable salt thereof, which is useful as an inhibitor for caspase.

[87] In the compound of formula (1) according to the present invention, R' preferably represents a side chain residue of all the natural amino acids, more preferably -CH

COCH. The compound of formula (1) may include the two kinds of stereoisomers, or mixtures thereof (diastereomeric mixtures) when the carbon to which R' is attached becomes a stereocenter due to the R' gmup. The compound of formula (1) may include an ester form (-CO z Y' wherein Y' is C i-C s-alky~, a sulfonamide form (-CONHSO z Y2 wherein Y2 is C-C -alkyl), and a pharmaceutically acceptable salt form, when R' is a side chain residue of an amino acid containing carboxyl moiety; or the compound of formula (1) may also exist in the form of a pharmaceutically acceptable salt when R' is a side chain residue of an amino acid containing a base moiety.

[88] The compound of the present invention (formula 1a) may exist in the form of a cyclic ketal (formula lb) when R' is -CH z COOH, and so a skilled artisan may understand that the cyclic ketal form (formula lb) may also be covered by the present invention.
[Chem.5]

R6, N R6, N

Formula 1a Formula lb [89] Also, the equilibrium forms of said compounds should be understood to cover their tautomeric forms.

[90] R2 preferably represents Ci-Cs-alkyl, more preferably methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl. The compound of formula (1) may include the two kinds of stereoisomers, or mixtures thereof (diastereomeric mixtures) when the carbon to which R2 is attached becomes a stereocenter due to the R2 gmup. The compound of formula (1) may include an ester form (-CO Y' wherein Y' is C-C -alkyl), a sulfonamide form (-CONHSO z Y2 wherein Y2 is C I -C s-alkyl), and a pharmaceutically acceptable salt form, when R2 is a side chain residue of an amino acid containing carboxyl moiety; or the compound of formula (1) may also exist in the form of a phar-maceutically acceptable salt when R2 is a side chain residue of an amino acid containing a base moiety.

[91] R3 preferably represents H, C i-C s-alkyl, C i-C s-alkoxy, or halogen, more preferably H, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl, methoxy, ethoxy, fluoro, or chloro.

[92] R4 preferably represents H.

[93] R5 preferably represents H.

[94] R6 preferably represents C 1-C 5-alkyl unsubstituted or substituted by C
3-C 10-cycloalkyl or aryl, each of which is substituted or unsubstituted; or represents substituted or un-substituted aryl. R6 more preferably represents C -C -alkyl unsubstituted or substituted by C 3-C 10-cycloalkyl or aryl, each of which is unsubstituted or substituted by one or more substituents selected from the gmup consisting of C-C -alkyl, hydroxy, C-C -alkoxy and halogen; or represents aryl which is unsubstituted or substituted by one or more substituents selected from the group consisting of C-C -alkyl, hydroxy, C-C -i s i s alkoxy and halogen. For example, R6 is phenyl, naphthyl, indolyl, quinolinyl, isoquinolyl, imidazolinyl, isoxazolyl, oxazolyl or thiazolyl; or is methyl substituted by phenyl, naphthyl, indolyl, quinolinyl, isoquinolyl, imidazolinyl, isoxazolyl, oxazolyl, thiazolyl or cyclohexyl, each of which is unsubstituted or substituted by one or more substituents selected from the graup consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, methoxy, ethoxy, trihalomethyl and halogen.

[95] R' and Rg each preferably represent H.

[96] R9 preferably represents aryl substituted by one or more halogens, more preferably phenyl substituted by one or more fluorines, and most preferably 2,3,5,6-tetrafluorophenyl.

[97] R10 preferably represents aryl substituted by one or more halogens, more preferably phenyl substituted by one or more chlorines, most preferably 2,6-dichlorophenyl.

[98] W preferably represents F.

[99] The most preferred compounds are those selected from the following group:

[100] 5-fluoro-3-[2-(4-methyl-2-oxo-l-phenyl-1,2-dihydro-pyridin-3-y~-butyrylamino]-4-oxo-pentanoic acid (1 ~

[101] 3-[2-(1-benzyl-4-methyl-2-oxo-1,2-dihydro-pyridin-3-y~-butyrylamino]-5-fluoro-4-oxo-pentanoic acid (2~

[102] 5-fluoro-3-[2-(4-methyl-2-oxo-l-phenethyl-1,2-dihydro-pyridin-3-yl)-butyrylamino]-4-oxo-pentanoic acid (3~

[103] 5-fluoro-3-[2-(1-isobutyl-4-methyl-2-oxo-1,2-dihydro-pyridin-3-y~-butyrylamino1-4 -oxo-pentanoic acid (4~

[104] 3-[2-(1-benzyl-2-oxo-1,2-dihydro-pyridin-3-yl)-butyrylamino]-5-fluoro-4-oxo-penta noic acid (5~

[105] 3-[2-(1-benzyl-2-oxo-1,2-dihydro-pyridin-3-y~-3-methyl-butyrylamino]-5-fluoro-4-oxo-pentanoic acid (6~

[106] 3-[2-(1-benzyl-2-oxo-1,2-dihydro-pyridin-3-yl)-pentanoylamino]-5-fluoro-4-oxo-pen tanoic acid (7~ and [107] 3-{2-[1-(2-tert-butyl-benzyl)-2-oxo-1,2-dihydro-pyridin-3-y1]-butyrylamino}-5-fluor o-4-oxo-pentanoic acid (8).

[108] The processes for preparation of the novel pyridone derivative of formula (1) showing an inhibitory activity against caspases are depicted in the following Reaction Schemes 1 to 4. However, those illustrated in the following Reaction Schemes represent only the typical processes used in the present invention. The manipulation order, reagent, reaction condition, solvent, etc. may be changed with no limit.

[109]

[110] ~ Reaction Scheme 1 ~
[Chem.6]

-~,NC CN NC HZSO4 OMe 0 CH2(CN)2 O I ~
MeO~R3 MeO R3 + MeO ~ R3 O O O O ro HN CN MeMgBr HN S HN N
I N(CH2CH2)20 C R3S

O
H2SO4, MeOH HN CCOz Me [111] As the Reaction Scheme 1 shows, acetylacetaldehyde dimethylacetal, malononitrile and piperidinium acetate are reacted in a suitable solvent, for example toluene, to give a mixture of propylidene malononitrile (2) and propenylidene malononitrile (3). This mixture is treated with conc. sulfuric acid to give pyridone carbonitrile (4).
This pyridone carbonitrile (4) is reacted with methyl magnesium bromide to give acetylpyridone (5). The acetylpyridone compound (5), sulfur and morpholine are reacted to give thioamide compound (6), which is then reacted with conc.
sulfuric acid in a suitable solvent, for example methanol, to give the desired pyridone compound (7). When R3 is H, the desired compound may be prepared according to a method known in JAmer. Chem. Soc., 1959, 81, 740-743.

[112]

[113] ~ Reaction Scheme 2 ~

[Chem.7]

O O
H,N CO2Me R6-Halide R6,N COzMe R2-Halide I _ I
R3 CS2CO3 R3 LiHMDS

LiOH
R6~N I COZMe R6,N COzH
~ R3 R3 [114] The compound (7) is reacted with a suitable alkyl halide to give the compound (8).
Thus obtained compound (8) is reacted with LiHMDS and a suitable alkyl halide to give the compound (9), which is then hydrolyzed, if necessary, to give the deprotected carboxylic acid compound (10).

[115]

[116] ~ Reaction Scheme 3 ~
[Chem.8]

O R2 13 O R2 O Dess-Martin R6, O R6, N N z N~ R30 HATU R30 O

R6,N N z TFA R6,N N z '~<
R30 O ~ \ I R30 O

(X = CH2Z) [117] In the Reaction Scheme 3 and the following Reaction Scheme 4, Z
represents -OR9 (R9 is C -C -alkyl, C -C -cyclcalkyl, or aryl), -OC(=O)R 10 (R'o is C -C -alkyl, C -C -cyclcalkyl, or aryl), or -W (W is halogen).

[118] As is shown in the Reaction Scheme 3, the carboxylic acid compound (10) is coupled with the aspartic acid compound (13) (see the following Reaction Scheme 4) to give the compound (11), which is then subjected to Dess-Martin periodene oxidation reaction and deprotection reaction, if necessary, to give the desired compound (1).

[119] The functional gmup Z in the compound (1) of Reaction Scheme 3 may be formed first by synthesizing the compound (13) already having the desired Z gmup according to the process of Reaction Scheme 4, and by reacting the compound (13) with the carboxylic acid compound (10) (see WO 00/23421). Or, the desired Z gmup may be introduced later according to the process of Reaction Scheme 4 after the carboxylic acid compound (10) is combined with the aspartic acid ((3-t-Bu) methyl ester and hydrolyzed. When Z is F, the racemic compound may be prepared according to a method known in Tetrahedron Letters, 1994, 35(52), 9693-9696.

[120]

[121] ~ Reaction Scheme 4 ~
[Chem.9]
O O O
CbzNHI"KOH ~ CbzNH J.Br CbzNH J~z Y" OtBu ~yOtBu \ /OtBu 0 0 p0 OH Hz OH
NaBH4 CbzNHI_~~z HZNz ~_/OtBu OtBu ~O( 0 [122] The compound of formula (1) according to the present invention has a brcad spectrum of inhibitory activity against caspases as demonstrated by the results of the following Experiments, and so has an effect for preventing inflammation and apoptosis. Thus, the present invention provides a pharmaceutical composition for inhibiting caspases, specifically a therapeutic composition for preventing inflammation and apoptcsis, comprising the compound of formula (1) or pharmaceutically acceptable salt thereof as an active ingredient together with the pharmaceutically acceptable carrier. Specifically, the composition of the present invention has a therapeutic or preventing effect for dementia, cerebral stroke, brain impairment due to AIDS, diabetes, gastric ulcer, cerebral injury by hepatitis, hepatitis-induced hepatic diseases, acute hepatitis, fulminant hepatic failure, sepsis, organ transplantation rejection, rheumatic arthritis, cardiac cell apoptosis due to ischemic cardiac diseases, or liver cirnccsis.

[123] Further, the present invention provides a use of the compound of formula (1) or phar-maceutically acceptable salt thereof for inhibiting caspase, specifically for preventing inflammation and apoptcsis. The present invention still further provides a method for preventing inflammation and apoptosis in a patient, which comprises administering a therapeutically effective amount of the compound of formula (1) or pharmaceutically acceptable salt thereof to the patient. The present invention still further provides a method for thetreatment or prevention of dementia, cerebral stroke, brain impairment due to AIDS, diabetes, gastric ulcer, cerebral injury by hepatitis, hepatitis-induced hepatic diseases, acute hepatitis, fulminant hepatic failure, sepsis, organ transplantation rejection, rheumatic arthritis, cardiac cell apoptosis due to ischemic cardiac diseases, or liver cirnccsis in a patient, which comprises administering a therapeutically effective amount of the compound of formula (1) or pharmaceutically acceptable salt thereof to the patient.

[124] The compound of formula (1) may be formulated into various pharmaceutical forms for administration purpose. To prepare the pharmaceutical compcsition according to the present invention, an effective amount of the compound of formula (1) or pharma-ceutically acceptable salt thereof is mixed with a pharmaceutically acceptable carrier that may be selected depending on the formulation to be prepared.

[125] The caspase inhibitor compound may be formulated as a parenteral injection, per-cutaneous or oral preparation, depending on its application purpcse. It is especially ad-vantageous to formulate the composition in a unit dcsage form for ease of admin-istration and uniformity of dosage.

[126] For the oral preparation, any usual pharmaceutical carrier may be used.
For example, water, glycols, oils, alcohols and the like may be used for such oral liquid preparations as suspensions, syrups, elixirs and solutions; or starches, sugars, kaolin, lubricants, binders, disintegrating agents and the like may be used for such solid preparations as powders, pills, capsules and tablets. Due to their ease of administration, tablets and capsules are the mcst advantageous dcsage unit forms. It is also desirable for tablets and pills to be formulated into enteric-coated preparation.

[127] For the parenteral preparation, sterile NAa.ter is usually used as the carrier, though other ingredients such as solubility aids may be used. Injections, for example, sterilized aqueous or oily suspension for injection, can be prepared according to the known procedure using suitable dispersing agent, wetting agent, or suspending agent.

Solvents that can be used for preparing injections include wter, Ringer's fluid, and isotonic NaC1 solution, and also sterilized fixing oil may be conveniently used as the solvent or suspending media. Any non-stimulative fixing oil including mono- or di-glyceride may be used for this purpose. Fatty acid such as oleic acid may also be used for injections.

[128] For the percutaneous administration, the carrier may include a penetration enhancing agent and/or a suitable wetting agent, optionally combined with suitable additives having no significant skin irritation. Said additives may facilitate the administration thmugh the skin and/or may assist preparation of a desired composition. These per-cutaneous preparations are administered via various manners, e.g., as a transdermal patch, a spot-on, or an ointment.

[129] When the caspase inhibitor of the present invention is used for clinical purpcse, it is preferable to administer to the subject patient in an amaunt ranging from 0.1 to 100 mg per kg of body weight a day. The total daily dcsage may be administered once or over several times. However, specific administration dosage for an individual patient can be varied with specific compound used, body weight, gender, hygienic condition, or diet of subject patient, time or method of administration, excretion rate, mixing ratio of agent, severity of disease to be treated, etc.

[130]

[131] ~ Mode for Invention ~

[132] The present invention will be more specifically explained by the following examples.
However, it should be understood that these examples are intended to illustrate the present invention but not in any manner to limit the scope of the present invention.

[133]

[134] Preparation 1-1) [135] 2-(3,3-Dimethoxy-l-methyl-propylidene)-malononitrile [136] Acetylacetaldehyde dimethylacetal (50 g, 378 mmol) and piperidinium acetate (5.5 g, 37.8 mmol) were dissolved in toluene (200 0 ), malononitrile (25 g, 378 mmol) NAas slowly added thereto over 20 min, and the mixture was stirred for 16 h at room temperature. The reaction mixture was NAa.shed with NAa.ter (100 0), dried (anhydnous sodium sulfate), and concentrated under reduced pressure to give a brown liquid compound (63 g, Yield: 92%), which was then identified by 'H-NMR as a mixture of 2-(3,3-dimethoxy-l-methyl-propylidene)- malononitrile and [(2E)-3-methoxy-l-methylprop-2-en-1-ylidene]malononitrile in about 10:1 ratio.

[137] ' H-NMR ( C1 , 400 MHz) 604.57 (t, 1H), 3.39 (s, 6H), 2.88 (d, 2H), 2.35 (s, 3H) [138]

[139] Preparation 1-2) [140] 4-Methyl-2-oxo-1,2-dihydro-pyridine-3-carbonitrile [141] To a 10:1 mixture of 2-(3,3-dimethoxy-l-methyl-propylidene)-malononitrile and [(2E)-3-methoxy-l-methylprop-2-en-1-ylidene]malononitrile (38 g, 211 mmo~ xAas added conc. sulfuric acid (34 0, 633 mmo~, and the mixture xAas stirred for 2 h at 50 C. The reaction mixture xAas cooled to room temperature, and xAater (100 0 ) was added thereto. The resulting soild compcund xAas filtered, xAashed with xAater (50 0 ), and dried to give the title compcund (21.1 g, Yield: 75%).

[142] 1 H-NMR (DMSO-d , 400 MHz) 6 12.31 (s, 1H), 7.65 (d, 1H), 6.30 (d, 1H), 2.36 (s, 3H) [143]

[144] Preparation 1-3) [145] 3-Acetyl-4-methyl-lH-pyridin-2-one [146] To methyl magnesium bromide (1.4 M toluene/tetrahydrofuran (75/25) solution, 327 0 , 458 mmo~ xAas added the compcund of Preparation 1-2) (20.5 g, 153 mmo~ for min under nitrogen atmosphere at room temperature, and the mixture xAas stirred under reflux for 3 h. The reaction mixture was cooled to room temperature, and stirred again for 12 h. The reaction mixture xAas slowly added to 6 N aqueaus hydrochloric acid solution (100 0 ) at 0 C, extracted, dried (anhydnous sodium sulfate), and con-centrated under reduced pressure. Diethyl ether (100 0 ) was added to the residue to give a pale yellow solid compcund, which xAas then filtered and dried to give the title compcund (21.7 g, Yield: 94%).

[147] ' H-NMR ( C1 , 400 MHz) 6 12.94 (s, 1H), 7.31 (d, 1H), 6.18 (d, 1H), 2.58 (s, 3H), 2.26 (s, 3H) [148]

[149] Preparation 1-4) [150] 4-Methyl-3-(2-morpholin-4-yl-2-thioxo-ethyl)-1H-pyridin-2-one [151] To 3-acetyl-4-methyl-lH-pyridin-2-one (21.5 g, 142 mmol) were added sulfur (4.79 g, 149 mmol) and morpholine (18.7 0 , 213 mmo~, and the mixture xAas heated to C for 8 h. The reaction mixture was cooled to room temperature. Ethanol (50 0 ) xAas added to give a grey solid compcund, which was then filtered and dried to give the title compcund (27.3 g, Yield: 76%).

[152] 1 H-NMR (DMSO-d , 400 MHz) 6 11.31 (s, 1H), 7.15 (d, 1H), 6.03 (d, 1H), 4.24 (t, 2H), 4.00 (t, 2H), 3.80 (s, 2H), 3.68 (m, 4H), 2.11 (s, 3H) [153]

[154] Preparation 1-5) [155] (4-Methyl-2-oxo-1,2-dihydro-pyridin-3-yl)-acetic acid methyl ester [156] To 4-methyl-3-(2-morpholin-4-yl-2-thioxo-ethy~-1 H-pyridin-2-one (27.3 g, 108 mmol) were added methanol (30 0 ) and conc. sulfuric acid (30 0 ), and the mixture was heated to 100 C for 3 h. The reaction mixture xAas cooled to room temperature, neutralized with saturated aquecus sodium carbonate solution, and passed through celite to remove the precipitates. The aquecus layer was extracted with methylene chloride (50 0 x 3), dried (anhydrous sodium sulfate), and concentrated under reduced pressure. Diethyl ether (100 0 ) was added to the residue to give a pale brown solid compcund, which xAas then filtered and dried to give the title compcund (16.9 g, Yield:
86%).

[157] ' H-NMR ( C1 , 400 MHz) 6 12.35 (s, 1H), 7.20 (d, 1H), 6.13 (d, 1H), 3.70 (s, 3H), 3.66 (s, 2H), 2.20 (s, 3H) [158]

[159] Preparation 1-6) [160] (4-Methyl-2-oxo-l-phenyl-1,2-dihydro-pyridin-3-yl)-acetic acid methyl ester [161] To a mixture of the compcund of Preparation 1-5) (181 mg, 1.0 mmol), phenylboronic acid (244 mg, 2.0 eq), Cu(OAc) .H O(40 mg, 0.2 eq), pyridine (0.16 0 , 2.0 eq), TEMPO (172 mg, 1.1 eq) and molecular sieve (100mg, 4A, powder, pre-dried) was added CH Cl (10 0 ), and the mixture was stirred for 1 h under nitrogen gas at room temperature. The reaction mixture xAas then expcsed to air, and stirred for 1 day. Saturated ammonium acetate (30 0 ) was added thereto, and the mixture was extracted twice with ethyl acetate (100 0 ). The extract was xAashed with aquecus sodium hydrogen carbonate solution of a low concentration (NaHCO 3 , 100 0 x 2), dried (anhydnaus Na SO ), and concentrated under reduced pressure. The residue was purified by column chromatography (30-60% ethyl acetate-hexane) to give the title compcund (236mg, Yield 92%).

[162] ' H-NMR (500MHz, Cl )6 7.47-7.44(m, 2H), 7.40-7.35 (m, 3H), 7.21(d, 1H), 6.12(d, 1H), 3.69(s, 3H), 3.68(s, 2H), 2.23(s, 3H) [163]

[164] Preparation 1-7) [165] 2-(4-Methyl-2-oxo-l-phenyl-1,2-dihydro-pyridin-3-yl)-butyric acid methyl ester [166] The compcund of Preparation 1-6) (230 mg, 0.89 mmo~ xAas dissolved in anhydrous THF (10 0 ) under nitrogen gas. 1.0M LiHMDS/THF (1.07 0 , 1.2 eq) was added thereto, and the mixture NAas stirred for 10 min while maintaining the temperature at -78 C. Then, ethyl iodide (0.11 0 , 1.5 eq) NAas added, and stirred for 2 h during which the mixture was slowly wrmed to room temperature. Water (20 0 ) NAas added, and the mixture was extracted with ethyl acetate (50 0 x 2), washed with aqueous sodium chloride solution (100 0 ), dried (anhydrous Na SO ), and concentrated under reduced pressure to give 260 mg of the title compound in a stoichiometric yield. This compound was used in the next reaction without further purification.

[167] ' H-NMR (500MHz, C1 )6 7.44(t, 2H), 7.40-7.34(m, 3H), 7.18 (d, 1H), 6.09(d, 1H), 3.77(dd, 1H), 3.65(s, 3H), 2.29-2.20(m, 1H), 2.23(s, 3H), 1.87(m, 1H), 0.91(t, 3H) [168]

[169] Preparation 1-8) [170] 2-(4-Methyl-2-oxo-l-phenyl-1,2-dihydro-pyridin-3-yl)-butyric acid [171] The compound of Preparation 1-7) (253mg, 0.89mmo~ was dissolved in a solvent mixture (6 0, tetrahydrofuran:MeCH:H20 = 3:2:1), LiCH.H20 (112 mg, 3.0 eq) NAas added, and the mixture was heated and stirred for about 4 h. The reaction mixture NAas neutralized by 1N aqueous hydrochloric acid solution, and distilled under reduced pressure to remove most tetrahydrofuran. The residue ws dissolved in excess ethyl acetate (50 0 ), NAa.shed with aqueous sodium chloride solution, dried (anhydrous Na SO ), and concentrated under reduced pressure to give the title compound (240 mg) in a stoichiometric yield. This compound was used in the next reaction without further purification.

[172] ' H-NMR (500MHz, Cl )6 7.53(t, 2H), 7.47(m, 1H), 7.37(d, 2H), 7.32(d, 1H), 6.37(d, 1H), 2.39(s, 3H), 2.29(m, 1H), 2.03(m, 2H), 0.95(t, 3H) [173]

[174] Preparation 1-9) [175] 5-Fluoro-3-[2-(4-methyl-2-oxo-l-phenyl-1,2-dihydro-pyridin-3-yl)-butyrylamino ]-4-oxo-pentanoic acid tert-butyl ester [176] A mixture of the carboxylic acid derivative obtained in Preparation 1-8) (240 mg, 0.89 mmo~, 3-amino-5-fluoro-4-hydroxy-pentanoic acid tert-butyl ester (see Tetrahedron Letters, 1994, 35(52), 9693-9696, 213 mg, 1.3 eq) and HATU (406 mg, 1.2 eq) NAas cooled to 0 C, triethylamine (0.50 0 , 4.0 eq) in DMF solvent (5 0 )NAa.s added thereto, and the mixture NAas reacted for 1 day. The solvent NAas distilled under reduced pressure. The residue was extracted with ethyl acetate (30 0 x 2), wshed with NAa.ter, aqueous sodium hydrogen carbonate solution and aqueous sodium chloride solution, dried (anhydrous Na 2 SO 4 ), and concentrated under reduced pressure. To the compound thus obtained and Dess-Martin reagent (755 mg, 2.0 eq) NAas added anhydnous dichloromethane (4 0 ), and the mixture was stirred at room temperature for 1 h. Isopropyl alcohol (1 0 ) was added to stop the reaction. The reaction mixture was filtered through celite under reduced pressure to remove the solid, and extracted with ethyl acetate (20 0 x 2). The extract was NAa.shed with water, saturated sodium hydrogen carbonate solution and aqueous sodium chloride solution, dried (anhydrous Na SO ), and concentrated under reduced pressure. The residue was purified by column chromatography (30-50% ethyl acetate-hexane) to give the title compound (298 mg, Yield 73%).

[177] ' H-NMR (500MHz, C1 )6 7.86(br s, 1H), 7.36-7.22(m, 5H), 7.15(t, 1H), 6.08(m, 1H), 5.23-4.82(m, 2H), 4.75(m, 1H), 3.75(m, 1H), 2.90-2.60 (m, 2H), 2.34 &
2.33(two s, 3H), 2.30-1.98(m, 2H), 1.40 & 1.38(two s, 9H), 0.87(m, 3H) [178]

[179] Example 1) [180] 5-Fluoro-3-[2-(4-methyl-2-oxo-l-phenyl-1,2-dihydro-pyridin-3-yl)-butyrylamino ]-4-oxo-pentanoic acid [Chem.10]
O O
c1N5~INF
O O
O

[181] The compound of Preparation 1-9) (240mg, 0.524mmo~ was dissolved in dichloromethane (4 0 ), and trifluorcacetic acid (2 0 ) was added thereto at 0 C. The reaction mixture NAas stirred for 1 h while being slowly warmed to room temperature, and concentrated under reduced pressure. The residue was purified by column chro-matography (10% methanol-dichloromethane) to give the title compound (179 mg, Yield 85%).

[182] ' H-NMR (500MHz, DMSO-d ) 6 7.81(m, 1H), 7.46(m, 3H), 7.39(m, 1H), 7.31(m, 2H), 6.21(t, 1H), 5.30-4.80(m, 2H), 4.57-4.45(m,1H), 3.54(m, 1H), 2.66-2.47(m, 2H), 2.17(s, 3H), 2.05-1.68(m, 2H), 0.74(m, 3H) [183]

[184] Preparation 2-1) [185] (1-Benzyl-4-methyl-2-oxo-1,2-dihydro-pyridin-3-yl)-acetic acid methyl ester [186] To a mixture of the compcund of Preparation 1-5) (544 mg, 3.0 mmo~ and NaH
(60% dispersed in mineral oil, 132 mg, 1.1 eq) was added DMF (5 0 ), and the mixture was stirred for 10 min at 0 C. Benzyl bromide (0.36 0 , 1.0 eq) xAas added thereto, and the mixture xAas stirred for 2 h under nitrogen gas at room temperature.
The reaction mixture was concentrated under reduced pressure, and the residue was extracted twice with ethyl acetate (100 0 ). The extract was xAashed with saturated sodium hydrogen carbonate solution (NaHCO 100 0 x 2) and aquecus sodium chloride solution, dried (anhydraus Na SO ), and concentrated under reduced pressure.

The residue xAas purified by column chromatography (30-50% ethyl acetate-hexane) to give the title compcund (676 mg, Yield 83%).

[187] ' H-NMR (500MHz, Cl )6 7.35-7.26 (m, 5H), 7.10(d, 1H), 6.02(d, 1H), 5.12 (s, 2H), 3.70 (s, 3H), 3.67(s, 2H), 2.16(s, 3H) [188]

[189] Preparation 2-2) [190] 2-(1-Benzyl-4-methyl-2-oxo-1,2-dihydro-pyridin-3-yl)-butyric acid methyl ester [191] The compcund of Preparation 2-1) (271 mg, 1.0 mmo~ was dissolved in anhydraus THF (6 0 ) under nitrogen gas. 1.OM LiHMDS/THF (1.1 0 , 1.1 eq) was added thereto, and the mixture xAas stirred for 10 min while maintaining the temperature at -78 C. Then, ethyl iodide (0.210 , 1.5 eq) xAas added, and stirred for 2 h during which the mixture was slowly Aarmed to room temperature. Saturated ammonium acetate solution xAas added to stop the reaction. The reaction mixture was extracted with ethyl acetate (50 0 x 2), xAashed with aquecus sodium chloride solution (100 0 ), dried (anhydreus Na 2 SO 4 ), concentrated under reduced pressure, and purified by column chromatography (40-50% ethyl acetate-hexane) to give the title compcund (142 mg, Yield 47%).

[192] ' H-NMR (500MHz, Cl )6 7.34-7.22 (m, 5H), 7.06(d, 1H), 5.98(d, 1H), 5.18-5.01 (ABq, 2H), 3.72 (dd, 1H), 3.63(s, 3H), 2.24(m, 1H), 2.17(s, 3H), 1.85(m, 1H), 0.88(t, 3H) [193]

[194] Preparation 2-3) [195] 2-(1-Benzyl-4-methyl-2-oxo-1,2-dihydro-pyridin-3-yl)-butyric acid [196] The compcund of Preparation 2-2) (140mg, 0.468mmo~ was dissolved in a solvent mixture (10 0 , tetrahydrofuran:MeCH:H 2 O= 3:2:1), 1N LiCH.H 2 0 (1.4 0 , 3.0 eq) was added, and the mixture NAas heated and stirred for about 5 h. The reaction mixture ws neutralized by 1N aqueous hydrochloric acid solution, and distilled under reduced pressure to remove most tetrahydrofuran. The residue ws dissolved in excess ethyl acetate (50 0 ), NAa.shed with aqueous sodium chloride solution, dried (anhydmus Na SO4), and concentrated under reduced pressure to give the title compound (134mg, Yield 100%). This compound NAas used in the next reaction without further pu-rification.

[197] ' H-NMR (500MHz, C1 ) 6 7.34-7.21 (m, 6H), 6.26(d, 1H), 5.24-5.14 (ABq, 2H), 3.79 (t, 1H), 2.29(s, 3H), 2.27(m, 1H), 2.00(m, 1H), 0.92(t, 3H) [198]

[199] Preparation 2-4) [200] 3-[2-(1-Benzyl-4-methyl-2-oxo-1,2-dihydro-pyridin-3-yl)-butyrylamino]-5-fluoro -4-oxo-pentanoic acid tert-butyl ester [201] A mixture of the carboxylic acid derivative obtained in Preparation 2-3) (133 mg, 0.468 mmo~, 3-amino-5-fluoro-4-hydroxy-pentanoic acid tert-butyl ester (see Tetrahedron Letters, 1994, 35(52), 9693-9696, 116 mg, 1.2 eq) and HATU (213 mg, 1.2 eq) NAas cooled to 0 C in DMF solvent (5 0 ), triethylamine (0.26 0 , 4.0 eq) NAas added thereto, and the mixture NAas reacted for 2 h at room temperature. The solvent was distilled under reduced pressure. The residue NAas extracted with ethyl acetate (30 0 x 2), washed with water, aqueous sodium hydrogen carbonate solution and aqueous sodium chloride solution, dried (anhydnous Na SO ), and concentrated under reduced pressure. The residue NAas purified by column chromatography (40-60% ethyl acetate-hexane) to give 3-[2-(1-benzyl-4-methyl-2-oxo-1,2-dihydro-pyridin-3-yl)- bu-tyrylamino]-5-fluoro-4-hydroxy-pentanoic acid tert-butyl ester (140 mg, Yield 63%).
To this compound and Dess-Martin reagent (184 mg, 1.5 eq) NAas added anhydnous dichloromethane (4 0 ), and the mixture was stirred for 1 h at room temperature.
Isopropyl alcohol (1 0 )NAa.s added to stop the reaction. The reaction mixture was filtered thmugh celite under reduced pressure to remove the solid, and extracted with ethyl acetate (20 0 x 2). The extract NAas NAa.shed with NAa.ter, saturated sodium hydrogen carbonate solution and aqueous sodium chloride solution, dried (anhydmus Na SO ), and concentrated under reduced pressure. The residue was purified by column chromatography (30-40% ethyl acetate-hexane) to give the title compound (110 mg, Yield 81%).

[202] ' H-NMR (500MHz, Cl ) 6 8.40(two br s, 1H), 7.36-7.22(m, 5H), 7.15(t, 1H), 6.08(m, 1H), 5.23-4.82(m, 4H), 4.75(m, 1H), 3.75(m, 1H), 2.88-2.60 (m, 2H), 2.28 &

2.27(two s, 3H), 2.28-2.04(m, 2H), 1.41 & 1.38(two s, 9H), 0.87(m, 3H) [203]

[204] Example 2) [205] 3-[2-(1-Benzyl-4-methyl-2-oxo-1,2-dihydro-pyridin-3-yl)-butyrylamino]-5-fluoro -4-oxo-pentanoic acid [Chem.11 ]

O O
N
N F
O
I ~ I O
71: ~
D
O

[206] The compcund of Preparation 2-4) (100mg, 0.212mmo~ NAas dissolved in dichloromethane (4 0 ), and trifluorcacetic acid (2 0 ) was added thereto at 0 C. The reaction mixture NAas stirred for 1 h while being slowly warmed to room temperature, and concentrated under reduced pressure. The residue was purified by column chro-matography (10% methanol-dichloromethane) to give the title compcund (60 mg, Yield 68%, white powder).

[207] ' H-NMR (500MHz, DMSO-d ) 6 12.40(br s, 1H), 7.74(m, 1H), 7.56(t, 1H), 7.26-7.21(m, 5H), 6.14(d, 1H), 5.30-4.65(m, 2H), 5.16(m, 1H), 4.91(m, 1H), 4.50-4.38(m, 1H), 3.50(m, 1H), 2.64-2.40(m, 2H), 2.13(s, 3H), 2.04-1.69(m, 2H), 0.69(m, 3H) [208]

[209] Preparation 3-1) [210] (4-Methyl-2-oxo-l-phenethyl-1,2-dihydro-pyridin-3-yl)-acetic acid methyl ester [211] To a mixture of the compcund of Preparation 1-5) (544 mg, 3.0 mmol) and NaH
(60% dispersed in mineral oil, 132 mg, 1.1 eq) was added DMF (5 0 ), and the mixture was stirred for 10 min at 0 C. Phenethyl bromide (0.45 0 , 1.1 eq) was added thereto, and the mixture NAas stirred for 2 h under nitrogen gas at room temperature.
The reaction mixture was concentrated under reduced pressure, and the residue was extracted twice with ethyl acetate (100 0 ). The extract was NAa.shed with saturated sodium hydrogen carbonate solution (NaHCO 3 , 100 0 x 2) and aquecus sodium chloride solution, dried (anhydreus Na SO ), and concentrated under reduced pressure.

The residue NAas purified by column chromatography (30-50% ethyl acetate-hexane) to give the title compcund (414 mg, Yield 48%).

[212] 1 H-NMR (500MHz, Cl )6 7.28-7.14 (m, 5H), 6.79(d, 1H), 5.89(d, 1H), 4.09(t, 3H), 3.71(s, 3H), 3.67(s, 2H), 3.03(t, 3H), 2.15(s, 3H) [213]

[214] Preparation 3-2) [215] 2-(4-Methyl-2-oxo-l-phenethyl-1,2-dihydro-pyridin-3-yl)-butyric acid methyl ester [216] The compcund of Preparation 3-1) (405 mg, 1.42 mmo~ was dissolved in anhydraus THF (6 0 ) under nitrogen gas. 1.0M LiHMDS/THF (1.70 0 , 1.2 eq) was added thereto, and stirred for 10 min while the reaction mixture was maintained at -78 C.
Then, ethyl iodide (0.17 0 , 1.5 eq) xAas added, and stirred for 2 h during which the mixture was slowly warmed to room temperature. Saturated ammonium acetate solution xAas added to stop the reaction. The reaction mixture was extracted with ethyl acetate (50 0 x 2), xAashed with aquecus sodium chloride solution (100 0 ), dried (anhydreus Na SO ), concentrated under reduced pressure, and purified by column chromatography (30-40% ethyl acetate-hexane) to give the title compcund (320mg, Yield 72%).

[217] ' H-NMR (400MHz, Cl )6 7.28-7.19(m, 5H), 6.74(d, 1H), 5.84(d, 1H), 4.13-4.06(m, 2H), 3.74(m, 1H), 3.68(s, 3H), 3.02(t, 2H), 2.25(m, 1H), 2.16(s, 3H), 1.85(m, 1H), 0.89(t, 3H) [218]

[219] Preparation 3-3) [220] 5-Fluoro-3-[2-(4-methyl-2-oxo-l-phenethyl-1,2-dihydro-pyridin-3-yl)-butyrylam ino]-4-oxo-pentanoic acid tert-butyl ester [221] The compcund of Preparation 3-2) (313mg, 1.0mmol) was hydrolyzed according to the same procedure as Preparation 2-3) to give a carboxylic acid derivative (296mg, 99%). A mixture of the carboxylic acid derivative thus obtained (290 mg, 0.97 mmo~, 3-amino-5-fluoro-4-hydroxy-pentanoic acid tert-butyl ester (see Tetrahedron Letters, 1994, 35(52), 9693-9696, 270 mg, 1.3 eq) and HATU (456 mg, 1.2 eq) was cooled to 0 C, triethylamine (0.56 0 , 4.0 eq) in DMF solvent (5 0 ) was added thereto, and the mixture was reacted for 1 day. The solvent xAas distilled under reduced pressure. The residue was extracted with ethyl acetate (30 0 x 2), xAashed with xAater, aquecus sodium hydrogen carbonate solution and aquecus sodium chloride solution, dried (anhydreus Na SO ), and concentrated under reduced pressure. The residue xAas purified by column chromatography (50-70% ethyl acetate-hexane) to give 5-fluoro-4-hydroxy-3-[2-(4-methyl-2-oxo-l-phenethyl-1,2-dihydro-pyridin-3-y~-butyrylamino]-pentanoic acid tert-butyl ester (232 mg, 49%). To this compound and Dess-Martin reagent (300 mg, 1.5 eq) was added anhydnous dichloromethane (4 0 ), and the mixture was stirred for 1 h at room temperature. Isopropyl alcohol (1 0 ) was added to stop the reaction. The reaction mixture was filtered thmugh celite under reduced pressure to remove the solid, and extracted with ethyl acetate (20 0 x 2). The extract was NAa.shed with NAa.ter, saturated sodium hydrogen carbonate solution and aqueous sodium chloride solution, dried (anhydmus Na SO ), and concentrated under reduced pressure. The residue NAas purified by column chromatography (40-50% ethyl acetate-hexane) to give the title compaund (170 mg, Yield 74%).

[222] ' H-NMR (500MHz, C1 )6 8.52 & 8.37(two br s, 1H), 7.28-7.20(m, 3H), 7.11(t, 2H), 6.77(two d, 1H), 5.92(m, 1H), 5.26-4.93(m, 2H), 4.79(m, 1H), 4.18-4.05(m, 2H), 3.75(m, 1H), 3.08-2.98(m, 2H), 2.93-2.66 (m, 2H), 2.25 & 2.24(two s, 3H), 2.28-2.06(m, 2H), 1.42 & 1.39(two s, 9H), 0.87(m, 3H) [223]

[224] Example 3) [225] 5-Fluoro-3-[2-(4-methyl-2-oxo-l-phenethyl-1,2-dihydro-pyridin-3-yl)-butyrylam ino]-4-oxo-pentanoic acid [Chem.12]
ONNF
O ~ ~ O OH

O

[226] The compound of Preparation 3-3) (165mg, 0.339mmo~ was dissolved in dichloromethane (4 0 ), and trifluorcacetic acid (2 0 ) was added thereto at 0 C. The reaction mixture NAas stirred for 1 h while being slowly warmed to room temperature, and concentrated under reduced pressure. The residue was purified by column chro-matography (80% ethyl acetate-hexane) to give the title compound (135 mg, Yield 92%, white powder).

[227] ' H-NMR (500MHz, DMSO-d ) 6 12.31(br s, 1H), 7.85-7.75(dd, 1H), 7.31(m, 1H), 7.24(m, 2H), 7.18-7.14(m, 3H), 6.02(t, 1H), 5.40-4.97(m, 2H), 4.58-4.42(m,1H), 4.07(m, 1H), 3.98(m, 1H), 3.48(m, 1H), 2.87(m, 2H), 2.72(m, 1H), 2.43(m, 1H), 2.11(m, 3H), 2.01-1.73(m, 2H), 0.69(m, 3H) [228]

[229] Preparation 4-1) [230] (1-Isobutyl-4-methyl-2-oxo-1,2-dihydro-pyridin-3-yl)-acetic acid methyl ester [231] To a mixture of the compcund of Preparation 1-5) (362 mg, 2.0 mmo~ and Cs CO

(977 mg, 1.5 eq) were added DMF (6 0 ) and isobutyl bromide (0.28 0 , 1.3eq), and the mixture was stirred for 1 day under nitrogen gas at 60 C. The reaction mixture was concentrated under reduced pressure, and the residue xAas extracted twice with ethyl acetate (100 0 ). The extract xAas xAashed with saturated sodium hydrogen carbonate solution (NaHCO , 100 0 x 2) and aquecus sodium chloride solution, dried (anhydrous Na 2 SO 4 ), and concentrated under reduced pressure. The residue xAas purified by column chromatography (30-50% ethyl acetate-hexane) to give the title compcund (224 mg, Yield 47%).

[232] ' H-NMR (500MHz, Cl )6 7.04(d, 1H), 6.00(d, 1H), 3.69(d, 2H), 3.68(s, 3H), 3.63(s, 2H), 2.16(s, 3H), 0.91(d, 6H) [233]

[234] Preparation 4-2) [235] 2-(1-Isobutyl-4-methyl-2-oxo-1,2-dihydro-pyridin-3-yl)-butyric acid methyl ester [236] The compcund of Preparation 4-1) (217 mg, 0.916 mmo~ was dissolved in anhydnaus THF (10 0 ) under nitrogen gas. 1.OM LiHMDS/THF (1.10 0 , 1.2 eq) was added thereto, and stirred for 10 min while the reaction mixture xAas maintained at -78 C. Then, ethyl iodide (0.11 0 , 1.5 eq) xAas added, and stirred for 2 h during which the mixture xAas slowly warmed to room temperature. Saturated ammonium acetate solution was added to stop the reaction. The reaction mixture xAas extracted with ethyl acetate (50 0 x 2), washed with aquecus sodium chloride solution (100 0 ), dried (anhydrous Na SO ), concentrated under reduced pressure, and purified by column chromatography (30-40% ethyl acetate-hexane) to give the title compcund (180mg, Yield 74%).

[237] ' H-NMR (500MHz, Cl )6 7.01(d, 1H), 5.96(d, 1H), 3.72-3.66(m, 3H), 3.63 (s, 3H), 2.21(m, 1H), 2.17(s, 3H), 2.12(m,1H), 1.84(m, 1H), 0.90-0.84(m, 9H) [238]

[239] Preparation 4-3) [240] 5-Fluoro-3-[2-(1-isobutyl-4-methyl-2-oxo-1,2-dihydro-pyridin-3-yl)-butyrylamin o]-4-oxo-pentanoic acid tert-butyl ester [241] The compcund of Preparation 4-2) (180mg, 0.679mmo~ xAas reacted according to the same procedure as Preparation 3-3) to give the title compound (149mg, Yield 50%).

[242] 1 H-NMR (500MHz, C1 )6 8.49 & 8.44(two br s, 1H), 7.07(m, 1H), 6.06 (m, 1H), 5.28-4.88(m, 2H), 4.76(m, 1H), 3.72(m, 3H), 2.89-2.62 (m, 2H), 2.27(m, 3H), 2.26-2.06(m, 3H), 1.42 & 1.38(two s, 9H), 0.90(m, 6H), 0.87(m, 3H) [243]

[244] Example 4) [245] 5-Fluoro-3-[2-(1-isobutyl-4-methyl-2-oxo-1,2-dihydro-pyridin-3-yl)-butyrylamin o]-4-oxo-pentanoic acid [Chem.13]
O O
N F
N

I O 1:
O
O

[246] The compound of Preparation 4-3) (143mg, 0.326mmo~ NAas dissolved in dichloromethane (4 0 ), and trifluorcacetic acid (2 0 ) was added thereto at 0 C. The reaction mixture NAas stirred for 1 h while being slowly warmed to room temperature, and concentrated under reduced pressure. The residue was purified by column chro-matography (80% ethyl acetate-hexane) to give the title compound (121 mg, Yield 97%, white powder).

[247] ' H-NMR (500MHz, DMSO-d ) 6 12.27(br s, 1H), 7.81-7.72(dd, 1H), 7.43(m, 1H), 6.08(m, 1H), 5.33-4.91 & 4.65-4.28(m, 3H), 3.71(m, 1H), 3.54-3.46(m, 2H), 2.70(m, 1H), 2.40(m, 1H), 2.12(s, 3H), 1.99-1.71(m, 2H), 0.78(s, 6H), 0.67(s, 3H) [248]

[249] Preparation 5-1) [250] (2-Oxo-1,2-dihydro-pyridin-3-yl)-acetic acid methyl ester [251] (2-Oxo-1,2-dihydro-pyridin-3-yl)-acetic acid (1.51g, 9.85mmo~ obtained by a method known in J. Amer. Chem. Soc. 1959, 81 , p740 NAas dissolved in MeOH (20 0 ), c-HC1 was added thereto, and the mixture was refluxed for 1 h. The reaction mixture was distilled under reduced pressure to give 1.65g of the title compound in a stoichiometric yield.

[252] ' H-NMR (500MHz, Cl ) 6 12.86(br s, 1H), 7.42 (d, 1H), 7.32 (dd, 1H), 6.26(t, 1H), 3.71 (s, 3H), 3.56(s, 2H) [253]

[254] Preparation 5-2) [255] (1-Benzyl-2-oxo-1,2-dihydro-pyridin-3-yl)-acetic acid methyl ester [256] To a mixture of the compcund of Preparation 5-1) (303 mg, 1.81 mmol) and Cs CO

(900 mg, 1.5 eq) were added DMF (4 0 ) and benzyl bromide (0.28 0 , 1.3eq), and the mixture was stirred for 1 day under nitrogen gas at 60 C. The reaction mixture was concentrated under reduced pressure, and the residue xAas extracted twice with ethyl acetate (100 0 ). The extract xAas xAashed with saturated sodium hydrogen carbonate solution (NaHCO , 100 0 x 2) and aquecus sodium chloride solution, dried (anhydrous Na SO ), and concentrated under reduced pressure. The residue xAas purified by column chromatography (30-50% ethyl acetate-hexane) to give the title compcund (360 mg, Yield 77%).

[257] ' H-NMR (500MHz, Cl ) 6 7.35-7.25 (m, 6H), 7.22 (d, 1H), 6.13(t, 1H), 5.14(s, 2H), 3.71 (s, 3H), 3.57(s, 2H) [258]

[259] Preparation 5-3) [260] 2-(1-Benzyl-2-oxo-1,2-dihydro-pyridin-3-yl)-butyric acid methyl ester [261] The compcund of Preparation 5-2) (80 mg, 0.311 mmo~ was dissolved in anhydrous THF (4 0 ) under nitrogen gas. 1.OM LiHMDS/THF (0.40 0 , 1.2 eq) was added thereto, and stirred for 10 min while the reaction mixture was maintained at -78 C.
Then, ethyl iodide (0.04 0 , 1.5 eq) xAas added, and stirred for 2 h during which the mixture was slowly warmed to room temperature. Saturated ammonium acetate solution xAas added to stop the reaction. The reaction mixture was extracted with ethyl acetate (50 0 x 2), xAashed with aquecus sodium chloride solution (100 0 ), dried (anhydrous Na SO ), concentrated under reduced pressure, and purified by column chromatography (30-40% ethyl acetate-hexane) to give the title compcund (33 mg, Yield 37%).

[262] ' H-NMR (500MHz, Cl )6 7.45-7.22 (m, 6H), 7.15(m, 1H), 6.14(t, 1H), 5.21-5.07 (ABq, 2H), 3.90 (t, 1H), 3.68(s, 3H), 2.00-1.76(m, 2H), 0.94(t, 3H) [263]

[264] Preparation 5-4) [265] 3-[2-(1-Benzyl-2-oxo-1,2-dihydro-pyridin-3-yl)-butyrylamino]-5-fluoro-4-oxo-pe ntanoic acid tert-butyl ester [266] The compcund of Preparation 5-3) (33mg, 0.116mmol) was reacted according to the same procedure as Preparation 3-3) to give the title compcund (42 mg, Yield 79%).

[267] ' H-NMR (500MHz, Cl ) 6 7.89 & 7.82(two br d, 1H), 7.35-7.22(m, 7H), 6.24(m, 1H), 5.28-4.65(m, 5H), 3.75(m, 1H), 2.91-2.58(m, 2H), 2.18(m, 1H), 1.72(m, 1H), 1.41 & 1.39(two s, 9H), 0.94(m, 3H) [268]

[269] Example 5) [270] 3-[2-(1-Benzyl-2-oxo-1,2-dihydro-pyridin-3-yl)-butyrylamino]-5-fluoro-4-oxo-pe ntanoic acid [Chem.14]

O H O
N N F
I / ~ I O OH

O

[271] The compcund of Preparation 5-4) (42mg, 0.092mmo~ was dissolved in dichloromethane (4 0 ), and trifluorcacetic acid (2 0 ) was added thereto at 0 C. The reaction mixture NAas stirred for 1 h while being slowly warmed to room temperature, and concentrated under reduced pressure. The residue was purified by Prep-chromatography (10% methanol/ dichloromethane) to give the title compcund (30 mg, Yield 81%, white powder).

[272] ' H-NMR (500MHz, DMSO-d ) 6 12.40(br s, 1H), 8.48(br s, 1H), 7.69(m, 1H), 7.34(m, 1H), 7.28-7.23(m, 5H), 6.23(m, 1H), 5.30-4.76(m, 2H), 5.08(m, 2H), 4.56-4.45(m, 1H), 3.57(m, 1H), 2.62-2.32(m, 2H), 1.72-1.56(m, 2H), 0.80(m, 3H) [273]

[274] Preparation 6-1) [275] 2-(1-Benzyl-2-oxo-1,2-dihydro-pyridin-3-yl)-3-methyl-butyric acid methyl ester [276] The compcund of Preparation 5-2) (174 mg, 0.676 mmo~ was dissolved in anhydnaus THF (10 0 ) under nitrogen gas. 1.OM LiHMDS/THF (1.00 0 , 1.5 eq) was added thereto, and stirred for 10 min while the reaction mixture NAas maintained at -78 C. Then, 2-iodopropane (0.12 0 , 1.8 eq) was added, and stirred for 0.5 h during which the mixture NAas slowly warmed to -50 C and for 1.5 h at 0 C. Saturated ammonium acetate solution NAas added to stop the reaction. The reaction mixture was extracted with ethyl acetate (50 0 x 2), washed with aquecus sodium chloride solution (100 0 ), dried (anhydreus Na 2 SO 4 ), concentrated under reduced pressure, and purified by column chromatography (25-30% ethyl acetate-hexane) to give the title compcund (95 mg, Yield 47%).

[277] ' H-NMR (500MHz, Cl ) 6 7.50(d, 1H), 7.35-7.25(m, 5H), 7.17(d, 1H), 6.15(t, 1H), 5.20-5.09(ABq, 2H), 3.96(d, 1H), 3.65(s, 3H), 2.22(m, 1H), 1.02(d, 3H), 0.84(d, 3H) [278]

[279] Preparation 6-2) [280] 3-[2-(1-Benzyl-2-oxo-1,2-dihydro-pyridin-3-yl)-3-methyl-butyrylamino]-5-fluoro -4-oxo-pentanoic acid tert-butyl ester [281] The compcund of Preparation 6-1) (95mg, 0.317mmol) was reacted according to the same procedure as Preparation 3-3) to give the title compcund (14 mg, Yield 97%).

[282] ' H-NMR (500MHz, Cl )6 7.94 & 7.81(two br s, 1H), 7.38-7.25(m, 7H), 6.23(m, 1H), 5.24-4.66(m, 5H), 3.40(two d, 1H), 2.86-2.58(m, H), 2.55(m, 1H), 1.41 &
1.40(two s, 9H), 1.04(two d, 3H), 0.78(d, 3H) [283]

[284] Example 6) [285] 3-[2-(1-Benzyl-2-oxo-1,2-dihydro-pyridin-3-yl)-3-methyl-butyrylamino]-5-fluoro -4-oxo-pentanoic acid [Chem.15]

O O
N N F
I / ~ I O O

O

[286] The compcund of Preparation 6-2) (132mg, 0.279mmo~ was dissolved in dichloromethane (4 0 ), and trifluorcacetic acid (2 0 ) was added thereto at 0 C. The reaction mixture xAas stirred for 1 h while being slowly warmed to room temperature, and concentrated under reduced pressure. The residue was purified by column chro-matography (60% ethyl acetate/hexane and 10% methanol/dichloromethane) to give the title compcund (94 mg, Yield 81%, white powder).

[287] ' H-NMR (500MHz, DMSO-d ) 6 12.40(br s, 1H), 8.63-8.52(dd, 1H), 7.66(m, 1H), 7.49(m, 1H), 7.27-7.21(m, 5H), 6.23(m, 1H), 5.21-4.86(m, 4H), 4.59-4.43(m, 1H), 3.54(m, 1H), 2.72-2.41(m, 2H), 2.10(m, 1H), 0.88(m, 3H), 0.69(m, 3H) [288]

[289] Preparation 7-1) [290] 2-(1-Benzyl-2-oxo-1,2-dihydro-pyridin-3-yl)-pentanoic acid methyl ester [291] The compcund of Preparation 5-2) (183 mg, 0.711 mmo~ was dissolved in anhydnaus THF (10 0 ) under nitrogen gas. 1.OM LiHMDS/THF (0.92 0 , 1.3 eq) was added thereto, and stirred for 10 min while the reaction mixture NAas maintained at -78 C. Then, n-propyl iodide (0.10 0 , 1.5 eq) NAas added, and stirred for 2 h during which the mixture NAas slowly warmed to room temperature. Saturated ammonium acetate solution was added to stop the reaction. The reaction mixture NAas extracted with ethyl acetate (50 0 x 2), washed with aqueous sodium chloride solution (100 0 ), dried (anhydrous Na SO ), concentrated under reduced pressure, and purified by column chromatography (30% ethyl acetate-hexane) to give the title compound (133 mg, Yield 62%).

[292] ' H-NMR (500MHz, Cl )6 7.36-7.27(m, 6H), 7.18(dd, 1H), 6.14(t, 1H), 5.21-5.08(ABq, 2H), 3.99(t, 1H), 3.67(s, 3H), 1.94(m, 1H), 1.73(m, 1H), 1.35(m, 2H), 0.92(t, 3H) [293]

[294] Preparation 7-2) [295] 3-[2-(1-Benzyl-2-oxo-1,2-dihydro-pyridin-3-yl)-pentanoylamino]-5-fluoro-4-oxo-pentanoic acid tert-butyl ester [296] The compound of Preparation 7-1) (130mg, 0.434mmo~ was reacted according to the same procedure as Preparation 3-3) to give the title compound (110 mg, Yield 54%).

[297] ' H-NMR (500MHz, Cl )6 7.88 & 7.82(two d, 1H), 7.34-7.24(m, 7H), 6.23(m, 1H), 5.24-4.64(m, 5H), 3.84(m, 1H), 2.89-2.56 (m, 2H), 2.13(m, 1H), 1.64(m, 1H), 1.41 & 1.38(two s, 9H), 0.92(m, 3H) [298]

[299] Example 7) [300] 3-[2-(1-Benzyl-2-oxo-1,2-dihydro-pyridin-3-yl)-pentanoylamino]-5-fluoro-4-oxo-pentanoic acid [Chem.16]

O H O
N N F
IO
I / ~ I OH

[301] The compound of Preparation 7-2) (110mg, 0.233mmo~ was dissolved in dichloromethane (4 0 ), and trifluorcacetic acid (2 0 ) was added thereto at 0 C. The reaction mixture NAas stirred for 1 h while being slowly warmed to room temperature, and concentrated under reduced pressure. The residue was purified by column chro-matography (10% methanoUdichloromethane) to give the title compound (58 mg, Yield 60%, white powder).

[302] ' H-NMR (500MHz, DMSO-d ) 6 8.44(br s, 1H), 7.68(m, 1H), 7.35(m, 1H), 7.30-7.23(m, 5H), 6.23(q, 1H), 5.22-4.66(m, 2H), 5.12-5.03(m, 2H), 4.55-4.45(m, 1H), 3.67(m, 1H), 2.62(m, 2H), 1.71-1.50(m, 2H), 1.20(m, 2H), 0.82(m, 3H) [303]

[304] Preparation 8-1) [305] 1-Bromomethyl-2-tert-butyl-benzene [306] To 1-tert-butyl-2-methyl-benzene (940 mg, 6.34 mmol), NBS (1.24 g, 1.1 eq) and AIBN (20 mg, catalytic amount) NAas added CC1 4 (12 0 ), and the mixture NAas refluxed for 1 h. The suspending particles were removed by filtration, and NAa.shed with CCl 4 . The combined organic layer NAas concentrated under reduced pressure to give 1.5 g of a yellow liquid in a stoichiometric yield.

[307] ' H-NMR (500MHz, C1 ) 6 7.46(m, 1H), 7.38(m, 1H), 7.22-7.21(m, 2H), 4.83(s, 2H), 1.46(s, 9H) [308]

[309] Preparation 8-2) [310] [1-(2-tert-Butyl-benzyl)-2-oxo-1,2-dihydro-pyridin-3-yl]-acetic acid methyl ester [311] To a mixture of the compound of Preparation 5-1) (177 mg, 0.598 mmol) and Cs 2 CO
(292 mg, 1.5 eq) were added DMF (6 0 ) and 1-bromomethyl-2-tert-butyl-benzene obtained in Preparation 8-1) (177mg, 1.3 eq), and the mixture was stirred for 3 h under nitrogen gas at 60 C. The reaction mixture NAas concentrated under reduced pressure, and the residue NAas extracted twice with ethyl acetate (100 0 ). The extract was washed with saturated sodium hydrogen carbonate solution (NaHCO 3 , 100 0 x 2) and aqueous sodium chloride solution, dried (anhydmus Na SO ), and concentrated under reduced pressure. The residue was purified by column chromatography (15-50%
ethyl acetate-hexane) to give the title compound (122 mg, Yield 65%).

[312] ' H-NMR (500MHz, Cl ) 6 7.46(d, 1H), 7.33(d, 1H), 7.25(t, 1H), 7.16(t, 1H), 6.97(d, 1H), 6.90(d, 1H), 6.11(t, 1H), 5.42(s, 2H), 3.73(s, 3H), 3.61(s, 2H), 1,43 (s, 9H) [313]

[314] Preparation 8-3) [315] 2-[1-(2-tert-Butyl-benzyl)-2-oxo-1,2-dihydro-pyridin-3-yl]-butyric acid methyl ester [316] The compound of Preparation 8-2) (120 mg, 0.383 mmo~ was dissolved in anhydnous THF (10 0 ) under nitrogen gas. 1.0M LiHMDS/THF (0.50 0 , 1.2 eq) was added thereto, and stirred for 10 min while the reaction mixture NAas maintained at -78 C. Then, ethyl iodide (0.05 0 , 1.5 eq) NAas added, and stirred for 2 h during which the mixture NAas slowly warmed to room temperature. Saturated ammonium acetate solution was added to stop the reaction. The reaction mixture NAas extracted with ethyl acetate (50 0 x 2), washed with aqueous sodium chloride solution (100 0 ), dried (anhydmus Na SO ), concentrated under reduced pressure, and purified by column chromatography (25-30% ethyl acetate-hexane) to give the title compound (50 mg, Yield 38%).

[317] ' H-NMR (500MHz, Cl ) 6 7.46(d, 1H), 7.36(d, 1H), 7.25(t, 1H), 7.16(t, 1H), 6.93(d, 1H), 6.88(d, 1H), 6.12(t, 1H), 5.48-5.34(ABq, 2H), 3.95(t, 1H), 3.63(s, 3H), 2.00(m, 1H), 1.83(m, 1H), 1,42(s, 9H), 0.95(t, 3H) [318]

[319] Preparation 8-4) [320] 3-{2-[1-(2-tert-Butyl-benzyl)-2-oxo-1,2-dihydro-pyridin-3-yl]-butyrylamino}-5-fl uoro-4-oxo-pentanoic acid tert-butyl ester [321] The compound of Preparation 8-3) (50mg, 0.146mmol) was reacted according to the same procedure as Preparation 3-3) to give the title compound (56 mg, Yield 76%).

[322] ' H-NMR (500MHz, C1 ) 6 7.89 & 7.80(two d, 1H), 7.47(d, 1H), 7.37(m, 1H), 7.25(t, 1H), 7.16(m, 1H), 7.01(t, 1H), 6.82(two d, 1H), 6.22(m, 1H), 5.48-5.36(m, 2H), 5.24-4.68(m, 3H), 3.77(m, 1H), 2.92-2.60(m, 2H), 2.18(m, 1H), 1.74(m, 1H), 1,43(two s, 9H), 1.41 & 1.37(two s, 9H), 0.95(m, 3H) [323]

[324] Example 8) [325] 3-{2-[1-(2-tert-Butyl-benzyl)-2-oxo-1,2-dihydro-pyridin-3-yl]-butyrylamino}-5-fl uoro-4-oxo-pentanoic acid [Chem.17]

O H O
N N F
I / ~ I O OH

O

[326] The compound of Preparation 8-4) (56mg, 0.110mmo~ was dissolved in dichloromethane (2 0 ), and trifluorcacetic acid (1 0 ) was added thereto at 0 C. The reaction mixture NAas stirred for 1 h while being slowly warmed to room temperature, and concentrated under reduced pressure. The residue was purified by Prep-chromatography (10% methanoUdichloromethane) to give the title compound (40 mg, Yield 80%, white powder).

[327] ' H-NMR (500MHz, DMSO-d ) 6 8.42(br s, 1H), 7.52(m, 1H), 7.43(t, 1H), 7.37(d, 1H), 7.15(t, 1H), 7.07(m, 1H), 6.56(d, 1H), 6.29(m, 1H), 5.33(m, 2H), 5.22-4.66(m, 2H), 4.56-4.45(m, 1H), 3.57(m, 1H), 2.61-2.46(m, 2H), 1.75-1.56(m, 2H), 1.40(s, 9H), 0.79(m, 3H) [328]

[329] Experiment 1 [330] Assay for the caspase inhibitory effect [331] Caspase-1 and caspase-8 known as cysteine proteases in the form of a z (3 z were expressed, purified, and activated by modifying a method known in Thornberry, N. A.
et al, Nature, 1992, 356, 768; Thornberry, N. A. Methods in Enzymology, 1994, 244, 615; Walker, N. P. C. et al. Cell, 1994, 78, 343, and caspase-9 ws also purified by a similar method, and the inhibitory activity against them ws tested. Briefly describing, plO and p20 subunits (Thornberry, N. A. et al, Nature, 1992, 356, 768) were expressed in E.coli and purified by nickel column and anionic exchange chromatography to give caspase-1, caspase-8 and caspase-9. The fluorescent substrates AcYVAD-AFC for thus obtained caspase-1, AcDEVD-AFC for caspase-8, and AcLEHD-AFC for caspase-9, were used for determining specific activity of the synthesized inhibitors.
The enzyme reaction was carried out at 25 C with various concentrations of the inhibitors in a buffer solution containing 50mM HEPES(pH 7.50), 10%(w/v) sucrese, 0.1%(w/v) CHAPS, 100mM NaC1, 1mM EDTA, and 10mM DTT in the presence of 50 M AcYVAD-AFC for lOnM caspase-1, 50 M AcDEVD-AFC for 2.1nM caspase-8, and 150 M AcLEHD-AFC for 200nM caspase-9. The inhibitory constants K and K
i of the inhibitors were determined by measuring the reaction velocity with the time obs lapse using a fluorescent spectrometer and by obtaining the initial rate constant. KNAas i calculated from the Lineweaver Burk Plot, and K from the following Equation 1.
obs [332]

[333] ~ Equation 1 ~

[334] K = -ln (1-A /A )/t obs t 00 [335] in which [336] A means cleavage rate (%) at time t, and t [337] A means the maximum cleavage rate (%).

[338] Spectra MAX GeminiXS Fluorescent Spectrometer of Molecular Device Co. ws used at the excitation wavelength of 405nm and the emission wavelength of 505nm.

[339] The in vivo inhibitory activity of the inhibitors ws determined by subjecting Jurkat cell (ATCC TIB-152) to apoptosis using Fas antibody (Upstate Biotech 05-201) and by detecting the color change according to the WST-1 method known in Francoeur A.M.
and Assalian A. (1996) Biochemica 3, 19-25 to observe the amount of alive Jurkat cells when the cells were treated by the inhibitor. Spectra MAX 340 Spectrometer of Molecular Device Co. NAas used at the absorbance wavelength of 440nm.

[340]

[341] (Table 11 Caspase-8 Jurkat Cell Example No. K bs/[1]
IC50 ( M) (M-'min i) 1 2.8 E4 4.90 2 1.1 E5 2.43 3 4.5 E4 4 4.4 E4 0.39 1.0 E6 0.81 6 2.1 E5 2.16 7 4.0 E5 0.64 8 2.0 E6 0.18 [342]

[343] Experiment 2 [344] Therapeutic effect for liver injury induced by Fas antibody in mouse [345] Step 1) Preparation of blood sample [346] Male Balb/c mice (6 weeks, Charles River Laboratory, Osaka, Japan ) were kept under the conditions of 22 C, 55% of relative humidity, and light-darkness cycle of 12 hours. Food and NAa.ter were supplied ad libitum. In pyrogen-free phcsphate buffer ws dissolved the Fas antibody (Jo2; BD pharmingen, San Diego, California), which was then injected to each mouce in the amount of 0.15 mg/kg through the vein of tail. Im-mediately after the injection of the Fas antibody, vehicle (a mixture of PEG400:
ethanol = 2: 1NAas 20-fold diluted with phcsphate buffer) wherein the test compound is dissolved or the vehicle alone NAas orally administered to the mice. After 6 hours from the drug administration, blood samples were obtained from their hearts.

[347]

[348] Step 2: Assay for the activity of plasma aminotransferase [349] The plasma ALT activity was determined for the blood samples obtained in Step 1 using ALT assay kit (Asan Pharm. Co., Seoul , Korea) according to the manufacturer's instruction. The results appeared that the injection of the Fas antibody sharply increases the ALT activity in plasma, and the test compounds inhibit the increased enzyme activity in a dose-dependent manner. Based on these results, ED values of so the test compounds were calculated using Prism softNAa.re of GraphPad Co. to give 0.001-10mg/kg.

[350]

[351] ~ Industrial Applicability ~

[352] As the above results of Experiments show, the compound of formula (1) of the present invention has an excellent inhibitory activity against caspase, and particularly exhibits a therapeutic effect in the animal model of liver injury induced by the Fas antibody. Therefore, the compound of formula (1) can be advantageously used for the treatment of various diseases and symptoms mediated by caspase.

Claims (14)

1. A compound of formula (1):

in which I) R1 represents H, C1-C5-alkyl, C3-C10-cycloalkyl, aryl, or a side chain residue of all the natural amino acids, II) R2 represents H, C1-C5-alkyl, C3-C10-cycloalkyl, aryl, or a side chain residue of all the natural amino acids, III) R3 represents H, C1-C5-alkyl, hydroxy, C1-C5-alkoxy, or halogen, IV) R4 represents H, C1-C5-alkyl, C3-C10-cycloalkyl, or aryl, V) R5 represents H, C1-C5-alkyl, C3-C10-cycloalkyl, or aryl, VI) R6 represents H, C1-C5-alkyl, C3-C10-cycloalkyl, or aryl, VII) R7 and R8 independently of one another each represent H, C1-C5-alkyl, C3-C
10-cycloalkyl, or aryl, VIII) X represents -CH OR9 (R9 is C1-C5-alkyl, C3-C10-cycloalkyl, or aryl), -CH
OC(=O)R10 (R10 is C1-C5-alkyl, C3-C10-cycloalkyl, or aryl), or -CH2-W (W is halogen), or pharmaceutically acceptable salt thereof.

2. The compound of Claim 1 wherein R6 represents C1-C5-alkyl unsubstituted or substituted by C3-C10-cycloalkyl or aryl, each of which is substituted or un-substituted; or represents substituted or unsubstituted aryl, or pharmaceutically acceptable salt thereof.

3. The compound of Claim 2 wherein R 6 represents C1-C5-alkyl unsubstituted or substituted by C3-C10-cycloalkyl or aryl, each of which is unsubstituted or substituted by one or more substituents selected from the group consisting of C5-alkyl, hydroxy, C1-C5-alkoxy and halogen; or represents aryl which is un-substituted or substituted by one or more substituents selected from the group consisting of C1-C5-alkyl, hydroxy, C1-C5-alkoxy and halogen, or pharma-ceutically acceptable salt thereof.

4. The compound of Claim 1 wherein I) R1 represents a side chain residue of all the natural amino acids, II) R2 represents C1-C5-alkyl, III) R3 represents H, C1-C5-alkyl, C1-C5-alkoxy, or halogen, IV) R4 represents H, V) R5 represents H, VI) R6 represents C1-C5-alkyl unsubstituted or substituted by C3-C10-cycloalkyl or aryl, each of which is unsubstituted or substituted by one or more substituents selected from the group consisting of C1-C5-alkyl, hydroxy, C1-C5-alkoxy and halogen; or represents aryl which is unsubstituted or substituted by one or more substituents selected from the group consisting of C1-C5-alkyl, hydroxy, C1-C5--alkoxy and halogen, VII) R7 and R8 independently of one another each represent H, VIII) X represents -CH OR9 (R9 is C1-C5-alkyl, C3-C10-cycloalkyl, or aryl), -OC(=O)R10(R10 is C1-C5-alkyl, C3-C10-cycloalkyl, or aryl), or -CH2-W (W is halogen), or pharmaceutically acceptable salt thereof.

5. The compound of Claim 1 wherein I) R1 represents -CH2COOH, 11) R2 represents C1-C5-alkyl, III) R3 represents H, C1-C5-alkyl, C1-C5-alkoxy, or halogen, IV) R4 represents H, V) R5 represents H, VI) R6 represents C1-C5-alkyl unsubstituted or substituted by C3-C10-cycloalkyl or aryl, each of which is unsubstituted or substituted by one or more substituents selected from the group consisting of C1-C5-alkyl, hydroxy, C1-C5-alkoxy and halogen; or represents aryl which is unsubstituted or substituted by one or more substituents selected from the group consisting of C1-C5-alkyl, hydroxy, C1-C5-alkoxy and halogen, VII) R7 and R8 independently of one another each represent H, VIII) X represents -CH2O-(2,3,5,6-tetrafluorophenyl), -CH2O-(2,6-dichlorobenzoyl) or -CH2-F, or pharmaceutically acceptable salt thereof.

6.3-{2-[1-(2-tert-Butyl-benzyl)-2-oxo-1,2-dihydro-pyridin-3-yl]-butyrylamino}-5-fluoro-4-oxo-pentanoic acid.

7. A pharmaceutical composition for inhibiting caspase, comprising the compound as defined in any one of Claims 1 to 6 or pharmaceutically acceptable salt thereof as an active ingredient together with a pharmaceutically acceptable carrier.

8. The composition of Claim 7 for preventing inflammation and apoptosis.

9. The composition of Claim 7 for the treatment or prevention of dementia, cerebral stroke, brain impairment due to AIDS, diabetes, gastric ulcer, cerebral injury by hepatitis, hepatitis-induced hepatic diseases, acute hepatitis, fulminant hepatic failure, sepsis, organ transplantation rejection, rheumatic arthritis, cardiac cell apoptosis due to ischemic cardiac diseases, or liver cirrhosis.

10. The composition of Claim 7 for the treatment of acute hepatitis or liver cirrhosis.

11. The composition of Claim 7 for the treatment of rheumatic arthritis.

12. A use of the compound as defined in any one of Claims 1 to 6 or pharma-ceutically acceptable salt thereof for inhibiting caspase.

13. A method for preventing inflammation and apoptosis in a patient, which comprises administering a therapeutically effective amount of the compound as defined in any one of Claims 1 to 6 or pharmaceutically acceptable salt thereof to the patient.

14. A method for the treatment or prevention of dementia, cerebral stroke, brain impairment due to AIDS, diabetes, gastric ulcer, cerebral injury by hepatitis, hepatitis-induced hepatic diseases, acute hepatitis, fulminant hepatic failure, sepsis, organ transplantation rejection, rheumatic arthritis, cardiac cell apoptosis due to ischemic cardiac diseases, or liver cirrhosis in a patient, which comprises administering a therapeutically effective amount of the compound as defined in any one of Claims 1 to 6 or pharmaceutically acceptable salt thereof to the patient.